Plant Science, 28(2006) 5:333-337
Ivan Kiryakov,and Dimitar Genchev
Dobroudja Agricultural Institute, 9520, General Toshevo, Bulgaria
ABSTRACT
Characterizing the pathogenicity of Xanthomonas axonopodis pv. phaseoli (Xap) is a main tool for the successful realization of DAI breeding program for resistance to common bacterial blight on bean. The pathogenicity of 11 fuscous and 9 normal Xap strains to 8 common bean varieties was investigated under field conditions. The varieties were sown in 1 m rows, 10 plants per row, in three replications for variety x strain. The leaves of the investigated varieties were inoculated at flowering stage by the multiple needle method. The response of the varieties was read 15 days after inoculation by a 9-degree scale: 1 - highly resistant; 9 - highly susceptible. The investigated isolates were grouped in two classes based on their virulence. The fuscous strains formed a separate class. Among the bean varieties included in this study, high resistance to the fuscous strains was demonstrated by line HR 45 and by the new released DAI variety Beslet.